bicentric quadrilateral construction with a ruler and no more than 6 lines
Source: 2004 Oral Moscow Geometry Olympiad grade 10 p3
October 28, 2020
geometrybicentric quadrilateralconstruction
Problem Statement
On the board was drawn a circle with a marked center, a quadrangle inscribed in it, and a circle inscribed in it, also with a marked center. Then they erased the quadrilateral (keeping one vertex) and the inscribed circle (keeping its center). Restore any of the erased vertices of the quadrilateral using only a ruler and no more than six lines.